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An Integrated Approach to Sustainable Roadside Design and Restoration

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4. Maintenance Considerations

An integrated approach to construction and maintenance is critical to ensuring long-term stability of the roadside system. As with many strategies featured in this guidebook, the best approach is to compare existing practices to sustainability strategies and to test new and innovative maintenance practices to achieve higher efficiency and more sustainable outcomes.

4.1 Introduction

A number of questions concerning maintenance should be asked initially during the design and construction process and revisited post-construction through long-term maintenance (FHWA Roadside Revegetation: An Integrated Approach to Establishing Native Plants, 2007):

• What are the maintenance goals for the project, and how will they be achieved?
• Are the financial resources in place to conduct adequate maintenance?
• How can maintenance costs be minimized?
• How will the maintenance process be improved over time through monitoring and feedback?

Maintenance needs to evolve over the life of a project. Thus, agencies need to be flexible and incorporate the capability to revise their approach if a strategy is not successful. Some strategies may need to be removed or reworked entirely, while others may become success stories that need to be recorded and replicated on future projects.

4.2 The Lifecycle

Maintenance is imperative to the long-term longevity of a healthy roadside environment. Often, strategies envisioned in the design and construction phase may present lower costs upfront but prove to be more expensive over a product's lifecycle when long-term (replacement) costs are factored in. This cost-benefit ratio is often measured through lifecycle costs.

A lifecycle is defined as "consecutive and interlinked stages of a product (or project) system, from raw material acquisition or generation from natural resources to final disposal or end of life" (ISO 2006a). Most lifecycle cost analyses are completed for pavement. The FHWA Interim Technical Bulletin Lifecycle Cost Analysis in Pavement Design (1998) provides a resource for calculating pavement lifecycle costs; another option is through FHWA's RealCost software.

Lifecycle analyses for elements of the roadside beyond the pavement are rarer. The Environmental Protection Agency (EPA) has a Framework for Responsible Decision-Making (FRED: 2000) which assesses lifecycle impacts by different impact categories, such as global warming potential, acidification, human health, etc. In addition, NCHRP Report 565 provides guidance for the selection of BMPs for highway run- off control (NCHRP, 2006). A spreadsheet model is included that simulates hydrologic impacts on BMP performance. Overall, additional investigation is needed on the lifecycle of roadside elements.

4.3 Recommended Process

To track roadside maintenance and ensure that strategies are executed, it is recommended that agencies complete roadside maintenance plans. Roadside maintenance plans designate tasks, responsibilities, schedules, and funding to ensure that all components of a roadside are considered. This plan should be enforceable but also flexible enough to adapt strategies to changing roadside conditions.

Roadside maintenance plans are typically prepared during the design process and revisited/updated during construction and operations. In order to identify and keep track of maintenance needs, a detailed inspection schedule should be established. An inspection schedule will identify items to be inspected and the frequency of inspection.

Roadside maintenance plans have a series of components, or steps, to ensure a thorough and integrated approach:

• Step 1 - Develop maintenance goals and objectives: These goals and objectives will vary by project context. Overarching goals should focus on prolonging the life of roadside facilities, minimizing extensive repairs, and ensuring long-term function and safety (Figure 4-1).
• Step 2 - Develop a maintenance strategy: A dedicated source of funding for maintenance is needed to understand the true costs of maintenance over time and the feasibility of various roadside features. An initial cost estimate should be prepared at the time of construction and evaluated by all entities responsible for maintenance.
• Step 3 - Develop a "living tool" to track maintenance activities: A roadside maintenance plan should include a tracking spreadsheet of all sustainable roadside commitments made and the level of maintenance required for each strategy. Supporting documentation to this spreadsheet might include, at a minimum, copies of inspection reports, invoices, financial records, and photographs of roadside facilities. Two of the critical pieces of information shown in Table 2 are the columns titled "Observations" and "Coordination with other disciplines." The "Observations" column is for maintenance personnel to record unusual circumstances or issues that may need attention. "Coordination with other disciplines" reflects a similar need to work with agency groups to ensure an integrated approach to maintenance and upkeep.
• Step 4 - Develop a protocol for tracking successes and failures: An important part of tracking maintenance activities is learning from sustainability strategies that have worked well and avoiding strategies that are not successful. An example spreadsheet in Table 2 shows how maintenance activities can be tracked over time. Data can be collected and evaluated annually to extract common themes, successes, and failures.

Figure 4-1 : Example of overgrown vegetation
Vegetation needs to be cleared from the guardrail to ensure safety and visibility (Cherohala Skyway between Tellico Plains, Tennessee, and Robbinsville, North Carolina).

Table 2: Maintenance Tracking Spreadsheet Example

Roadside Feature and Location	Maintenance Category*	Maintenance Strategy	Date Performed	Performed by	Materials Cost	Labor Hours	Observations	Coordination with other disciplines
Box Culvert; MP 101	Routine	Remove accumulated debris	6/1/2011	DOT Maintenance Division	$4,000	6	Need to visit more frequently	Need to work with Landscape Group concerning noxious weeds in culvert

*Example categories include preventive, routine, and remedial (non-routine).

4.4 Maintenance Checklist

Each of the disciplines discussed in this guidebook must consider maintenance. Maintenance personnel need to be educated on the selected maintenance strategies, embrace sustainability goals, and be part of the feedback process. The following lists specific items to consider under each discipline.

Hydraulic Design

Maintenance of hydraulic design features includes maintenance of ditches, side slopes, structures (drop inlets, pipe ends, culvert heads, etc.). Maintenance efforts for these features should ensure their long- term effectiveness in handling roadside drainage and keeping the traveling motorist safe. Stormwater facilities should be able to continue their function long-term and as originally designed. Lack of proper operation and maintenance is often cited as the number one reason for failure of stormwater facilities (Chester County Pennsylvania, 2004).

• Ensure that ditches remain traversable after cleaning.
• Clean ditches and structural features of debris and sediment regularly to prevent them from clogging and backing water onto the travel way (Figure 4-2).
• Ensure that side slopes do not become eroded over time. Plant native vegetation to slow erosion.
• Evaluate stormwater basins and other features for damage by burrowing animals or other wildlife.
• Avoid drainage features built above the ground which can cause injury if hit. Extend or relocate pipe, culvert, and other feature ends from the roadway to reduce the risk of a crash.

Geotech

Maintenance of side slopes and structural features, such as walls, are the key considerations under the Geotechnical discipline.

• Evaluate side slopes for any steepening due to erosion.
• Evaluate any erosion damage around roadside structures, such as walls, columns, abutments, and drainage structures.
• Evaluate the safety of steep slide slopes for their ability to handle errant vehicles; evaluate the quality of the recovery area (if present) at foot of embankment.

Vegetation

The goal for roadside revegetation is to create a stable, self-regulating vegetation system that requires minimal maintenance and low lifecycle costs. If left alone, vegetation can grow out of control, blocking driver visibility of signs, wildlife, and other potential hazards.

• Develop an integrated vegetation management (IVM) plan to set priorities and direct maintenance actions.
• Control invasive weeds.
• Improve soils to ensure long-term plant health.
• Manage living snow fences. Regularly inspect and control for insects, disease, and rodent problems and replant trees that do not survive.
• Keep vegetation away from guardrail to help the driver see the guardrail and to make it easier to inspect for needed repairs (FHWA W-Beam Guardrail Repair and Maintenance, 2008).

Safety

Maintenance of structural features along a roadway (guardrail, walls, etc.) helps to maintain driver safety and improve overall aesthetics.

• Maintain guardrail and fencing in good condition; inspect regularly (Figure 4-3).
• Repair damaged guardrail promptly to ensure safe travel.
• Maintain and repair roadside signs, safety devices, etc.
• Clear litter and collect trash from the roadside.

Figure 4-2: Example of a culvert clogged by sediment
(Source: Parsons Brinckerhoff, Capitol Reef Route 10, Utah)

Figure 4-3: Example of a guardrail not meeting safety requirements
(Source: Parsons Brinckerhoff, Cuba La Cueva, New Mexico)

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